A three-level T-type grid-connected inverter has been widely used in the current medium power distributed PV inverters, charging station and active power filter system with the advantages of high ...equivalent switching frequency, high efficiency, small filter inductance and grid current harmonic. However, the grid-connected inverter with LCL-filter is a third-order and multi-variable system, to meet the high-performance requirements for grid-connected current, claiming a higher requirement for the grid-current control system. Aiming at this, a new control strategy named capacitive current feedforward control based on the carrier-based PWM modulation scheme on is put forward. Further, to improve the power density, the capacitor current is generated indirectly calculated by the capacitor voltage. Finally, to verify the correctness and effectiveness of the proposed control strategy, a complete digital simulation model and experimental prototype platform is established, the detailed theoretical analysis and design method of the proposed control strategy are presented. The simulation and experimental results show that the steady and the transient performance of the grid current with the proposed control strategy are effectively improved, and no additional sensors are needed.
T307 V2G (Vehicle to Grid) charger is an important physical interface for EVs to provide V2G services to the grid. It not only has the charging function, but also has the function of feeding the ...power grid. The bi-directional charger with V2G service has a wide range of output power. The current ripple proportion at light-load becomes larger and the current response speed becomes slower, which will cause the zero-crossing distortion. And the traditional controller steady-state error will also increase, so that the grid side current harmonic proportion becomes larger lead to deteriorate in power quality. In this paper, a composite control strategy based on quasi proportional resonant (QPR) control and the weighted current (WC) control is presented. By simulation and experimental results, it is proved that this strategy has better harmonic suppression performance than traditional PI control methods, limited to 3.2%, which is conducive to the realization of electric vehicles feeding the smart grid cleanly.
In this letter, the Alamouti code combined with partial response signaling (PRS) is proposed. The bit error rate of the proposed quadrature PRS (QPRS) Alamouti code is derived for the quasi-static ...Rayleigh fading and additive white Gaussian noise channel. Furthermore, its performance in a severely bandlimited channel is simulated by using chopping filter and compared with the conventional Alamouti code. The numerical results show that the proposed QPRS Alamouti code outperforms the conventional Alamouti code under the chopping environment.
Plasmid QpRS from Coxiella burnetii, isolate Priscilla Q177, phase I, has been completely sequenced. DNA for sequencing was amplified with “extra-long” (XL) PCR. The size of the QpRS plasmid sequence ...was determined to be 39,280 bp, with a G + C content of 39.3%. Putative proteins associated with replication and recombination were identified. The sequence of QpRS plasmid was analyzed for shared and unique regions among C. burnetii plasmids.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
45.
Digital Modulations Michael Yang, Sung-Moon
Modern Digital Radio Communication Signals and Systems,
2018, 20180605
Book Chapter
We partition the communication signals into three – constellation, complex envelope (continuous I and Q baseband), and CW (real RF signal). Our focus in this chapter is on discrete-time ...representations, but we have to relate them to complex envelope and CW. This is done with binary cases – BPSK (2-PAM), OOK, and orthogonal (a form of FSK) using a rectangular pulse for converting to complex envelope and quadrature modulator to CW. Then binary modulations are extended to multi-level ones – PAM, QAM, and PSK. Additional topics that arise due to practical reasons are covered: offset QAM, scrambler, and 180° and 90° differential coding. PRS is an attempt to reduce the bandwidth. FSK is explored for noncoherent detection and its constant envelope property. The computation of PSD is explored analytically as well as numerically. Numerical simulation method is universally applicable even when no analytical solution is available.
List of sections in Chap. 2Constellation, Complex Envelope, and CWPower of Digitally Modulated Signals and SNRMAP and ML DetectorsPAM, QAM, and PSKBER and Different Forms of SNROffset QAM (or Staggered QAM)Digital Processing and Spectrum ShapingFrequency Modulation – FSK, MSK, and CPFSKPSD of Digitally Modulated SignalsChapter Summary and References
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FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A gene termed cbhE' was cloned from the QpH1 plasmid of Coxiella burnetii. Expression of recombinants containing cbhE' in vitro and in Escherichia coli maxicells, produced an insert-encoded ...polypeptide of approx. 42 kDa. The CbhE protein was not cleaved when intact maxicells were treated with trypsin. Hybridizations of total DNA isolated from the six strains of C. burnetii indicate that this gene is unique to C. burnetii strains associated with acute disease, i.e., HamiltonI, VaccaII, and RascheIII. The cbhE' gene was not detected in strains associated with chronic disease (BiotzereIV and CorazonV) or the DodVI strain. The cbhE' open reading frame (ORF) is 1022 bp in length and is preceded by a predicted promoter/Shine-Dalgarno (SD) region of TCAACT(-35)-N16-TAAAAT(-10)-N14-AGAAGGA (SD) located 10 nucleotides (nt) before the presumed AUG start codon. The ORF ends with a single UAA stop codon and has no apparent Rho-factor-independent terminator following it. The cbhE' gene codes for the CbhE protein of 341 amino acid (aa) residues with a deduced Mr of 39,442. CbhE is predominantly hydrophilic with a predicted pI of 4.43. The function of CbhE is unknown. No nt or aa sequences with homology to cbhE' or CbhE, respectively, were found in searches of a number of data bases.
In this paper, the Alamouti code combined with partial response signaling (PRS) is proposed. The bit error rate of the proposed quadrature PRS (QPRS) Alamouti code is derived for the quasi-static ...Rayleigh fading and additive white Gaussian noise channel. Furthermore, its performance in a severely bandlimited channel is simulated by using chopping filter and compared with the conventional Alamouti code. The numerical results show that the proposed QPRS Alamouti code outperforms the conventional Alamouti code under the chopping environment.
